A luxury superyacht carrying foreign tourists capsized and sank off Sicily in bad weather early Monday. One body was found, six people remain missing and 15 people were rescued, authorities said.

The ship had overturned around 5 a.m. off the port of Porticello, where it was apparently anchored. It had a crew of 10 people and 12 passengers, including British, American and Canadian nationalities, the Italian coast guard said. Local media said a sudden fierce storm, including tornados over water known as waterspouts, had battered the area overnight but skies were clear and seas calm by Monday morning.

The 56-meter (184-foot) British-flagged “Bayesian,” was known for its unusually single 75-meter (246-feet) mast, one of the world’s tallest made of aluminum. The online sites list it for charter for up to 195,000 euros (about $215,000) a week.

Eight of the people initially rescued and taken to shore at Porticello, near Palermo, were hospitalized. One body was found near the wreck, but six others were unaccounted for, said Luca Cari, a spokesperson for the Italian fire rescue service.

Rescue crews located the ship at a depth of 50 meters (163 feet) off Porticello and experienced deep-water police divers were trying to access the hull, Cari said. The operations, which were visible from shore, involved helicopters and rescue boats from the coast guard, fire rescue and civil protection service.

The seven who had not made it so far included one crew member and six passengers, the coast guard said.

The yacht, built in 2008 by the Italian firm Perini Navi, can accommodate 12 passengers in four double cabins, a triple and the master suite, plus crew accommodations, according to Charter World and Yacht Charters.

The vessel, which previously was named the “Salute” when it flew under a Dutch flag, featured a sleek, minimalist interior of light wood with Japanese accents designed by the French designer Remi Tessier, according to descriptions and photos on the sites.